As the matchmaking seems to work insides those GP brackets there are also guilds that try to stay exactly below the threshold for the next bracket. Our last enemy for example was at over 120M GP before the TW, then during the preview phase (they registered with 50 members) they dropped to 119.7M GP and now a day after they are back at 120.5M GP again. ^^ During the fighting we saw for example G11/12 GK with zero mods standing around, which leads me to the conclusion, that this was on purpose.